Asplenium onopteris
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Asplenium onopteris

Irish Spleenwort · Acute-leaved spleenwort · Western black spleenwort

Tier 1 Difficulty: hard Water: high Light: full_shade
Water every
7 days
Temperature
15–35 °C
Soil pH
5–7
Hardiness
Zone 7–10
Click count
13
Observations
615

Description

Source: leafsnap

Asplenium onopteris, commonly known as the Irish Spleenwort, is a fern species from the Aspleniaceae family. Native to Europe, it thrives in various habitats such as rocky cliffs, walls, and crevices. The plant features distinctive fronds that can grow up to 30 cm in length and 5 cm in width. These dark green, glossy fronds are pinnate, bearing numerous small leaflets that give them a feathery appearance. The Irish Spleenwort is an evergreen plant that can reach a height of up to 50 cm when fully mature. It prefers moist soil but can tolerate dry conditions once established. Historically, this fern has been used for its anti-inflammatory properties in traditional medicine. Easy to grow, Asplenium onopteris requires minimal care once established in a garden or landscape setting. It thrives in partial to full shade, making it ideal for planting under trees or other shaded areas of the garden. In summary, Asplenium onopteris (Irish Spleenwort) is an attractive evergreen fern native to Europe. Known for its distinctive feathery fronds and medicinal anti-inflammatory properties, it has been valued since ancient times.

Care Guide

💧 Water Every 7 days

Western black spleenwort thrives in conditions with moderate moisture. It needs soil that is consistently damp but not waterlogged. To ensure this, water the plant twice a week and maintain high humidity levels by misting or using pebble trays. Typically grown indoors, this plant benefits from well-balanced moisture to achieve optimal growth and enhance its ornamental beauty.

Suggested frequency: Every 7 days
FAQ
What should I do if I give my Western black spleenwort plant too much water or too little water?

The Western black spleenwort, a plant that loves water, can get overwatered if it's left sitting in a pool of water or in a planter without drainage holes. This leads to overly wet conditions, preventing the roots from getting nutrients and moisture. It can also cause fungal or bacterial diseases. Signs of overwatering include wilted and yellow leaves, drooping or mushy stems. However, it's important to check for other causes since overwatering is difficult for this plant. On the other hand, if the Western black spleenwort is not given enough water, it can quickly change from being lush and green to brown and crispy. In extreme cases, the plant may dry up completely, but there is still a chance to save it if some roots are healthy. To do so, remove all dry and dead stems, water thoroughly, and return it to its usual spot. The plant can recover and start growing new fronds, although it may take several months to regain its original size with proper care.

How do I properly water my Western black spleenwort?

The Western black spleenwort thrives in consistently moist soil similar to its native environment. It is crucial to water this plant regularly, even as frequently as every one or two days. Avoid letting the soil dry out by watering it again once the top layer feels slightly dry. When giving water, make sure to thoroughly soak the soil until water drains out from the bottom of the pot. Afterward, remove any excess water to prevent the pot from sitting in a puddle. Following this method will help maintain the ideal moisture for the soil and prevent it from becoming too dry.

What things should I think about when watering my Western black spleenwort?

The humidity levels in the air around your Western black spleenwort affect how often you need to water it. Higher humidity means less frequent watering because evaporation is slower. Avoid placing the plant near a heating or cooling vent as it will dry out too quickly. Instead, choose a location that is protected from drafts. These ferns prefer dappled and indirect sunlight and temperatures between 55-80 degrees F (13-27 degrees C). Placing them in a warm and sunny spot like a windowsill could lead to dehydration. Rainwater or distilled water is best for this plant, but tap water usually works fine in most places. Tap water, however, can cause brown leaf tips due to certain minerals and chemicals. Western black spleenwort has thin and delicate leaves, making it more susceptible to these issues. Avoid using small pots for this plant as they dry out too quickly. Give it more space in the pot compared to other houseplants. Consider using a self-watering planter for the Western black spleenwort. This type of pot has a wicking system that continuously soaks up water from a reservoir, keeping the soil consistently moist. It saves you from constantly watering the fern and benefits the roots by providing a steady water supply instead of fluctuating between dry and wet conditions.

☀️ Light Full shade

Garden specimens of the western black spleenwort strongly prefer sites with minimal light. Their growth, both in the wild and in cultivated conditions that mimic their native habitat, prospers in reduced light. Excessive light exposure can potentially damage the plants, whereas insufficient light may not affect their overall health.

Ideal: Full shade
FAQ
What are the sunlight requirements for Western black spleenwort?

Western black spleenwort requires full shade, meaning it should receive less than 3 hours of sunlight daily. Observing how sunlight moves through your garden can help you find the perfect balance of light and shade for these plants, ensuring their happiness. The plant shows a strong disposition towards areas with minimal light exposure and thrives in environments that mimic its native habitat, which feature diminished light. Too much exposure to sunlight can harm the vegetation, though it can tolerate underexposure without significant health effects.

How can artificial lighting benefit indoor specimens of Western black spleenwort?

When natural sunlight is insufficient for indoor specimens of Western black spleenwort, especially during winter or in less sunny spaces, artificial lighting can provide a vital solution. Adequate lighting promotes faster, healthier growth. LED lights are recommended as they can be customized to provide specific wavelengths of light needed by the plant. Full sun plants require 30-50W/sq ft, partial sun plants need 20-30W/sq ft, and full shade plants should have 10-20W/sq ft of artificial light. The light source should be placed 12-36 inches above the plant and turned on for 8-12 hours per day to mimic natural sunlight conditions.

What are the symptoms of light deficiency in Western black spleenwort?

Symptoms of light deficiency in Western black spleenwort include small leaves that are smaller in size than previous ones, leggy or sparse growth with longer spaces between leaves or stems resulting in a stretched-out appearance, faster leaf drop as the plant sheds older leaves early to conserve resources, slower or no new growth indicating the plant's survival mode in poor light conditions, and lighter-colored new leaves showing a lack of chlorophyll and essential nutrients. Although the plant can tolerate low light, providing adequate light ensures optimal growth and health.

What are the symptoms and solutions for Western black spleenwort when exposed to too much light?

Exposure to excessive sunlight can cause symptoms such as chlorosis, where leaves lose their green color and turn yellow, sunscald with pale, bleached areas on plant tissue, leaf curling as a defense mechanism to reduce surface area exposed to sunlight, wilting due to increased water loss, and leaf scorching characterized by brown, dry edges on leaves. Solutions include moving indoor plants to receive ample filtered light, using artificial light if necessary, and for outdoor plants, gradually moving them to sunnier locations to avoid sunburn. Removing obstructions that block sunlight and transplanting smaller plants to sunnier locations can also help.

🌡️ Temperature 15–35°C

Western black spleenwort does best in forest thickets. It is very sensitive to temperature and humidity; high temperatures, dry conditions, and strong sunlight can all stress the plant. In summer it needs adequate shading and a humid environment. Generally it does not need special care in winter, but an extended winter drought can still be fatal.

Ideal temperature: 15–35°C
FAQ
What is the Western black spleenwort?

The Western black spleenwort, known botanically as Asplenium onopteris, is a plant species recognized by its unique characteristics. However, there are no specific details provided about its essentials or symptoms associated with this entry.

💨 Humidity
Humidity:
🪴 Soil 5-7
Soil pH: 5-7
🌱 Fertilizer

To ensure optimal growth of the western black spleenwort, apply high-nitrogen fertilizers every 4 to 6 weeks during its active growth period. Use a diluted solution to prevent root burn, and reduce the frequency of fertilization during dormant seasons. Always follow the manufacturer's dosing instructions to promote healthy fronds and overall plant vigor, taking care not to overfeed and harm the delicate roots.

🪴 Pot & Repot
✂️ Pruning

The Western black spleenwort is characterized by its delicate, dark green fronds. For optimal growth, it benefits from pruning in early spring. By removing dead leaves and overcrowded fronds, you can enhance its growth and improve air circulation. This not only helps maintain its natural form but also reduces the risk of disease, promoting robust overall development.

🌿 Propagating
🐛 Diseases & pets
☠️ Toxicity

Characteristics

Plant Type
Fern
Life Cycle
Perennial
Genus
Asplenium
Family
Aspleniaceae
Hardiness Zone
7-10
Mature Height
20 cm to 40 cm
Mature Spread
30 cm to 49 cm
Leaf Color
Dark Green
Leaf Type
Evergreen
Planting Time
Spring, Autumn
Native Area
Libya, Turkey, Tunisia, Montenegro, Cyprus, Bulgaria, Poland, Greece, Croatia, Morocco, Lebanon, Portugal, Syria, Italy, Spain, Iran, Albania, Ireland, Algeria, France

Tags (5)

Common Names (3)

en Irish Spleenwort
en Acute-leaved spleenwort
en Western black spleenwort